The present invention relates to an attachment device, especially for releasably attaching a cover to an engine housing of a power-driven tool such as a motor saw, comprising at least one spring clip adapted to be releasably connected to the engine housing and/or the cover, and a guide pin attached to the engine housing or the cover adjacent to the spring clip and adapted to engage in a complementary recess in the cover or engine housing.
For attaching a cylinder cover to a motor chain saw, for example, it is preferable to use spring clips that can easily and quickly be clamped and released, to facilitates the attachment and removal of the cover. In chain saws and similar tools having an internal combustion engine, however, secure attachment of the cover encounters problems caused by engine vibrations. Such vibrations result in mutual movement of the interengaging surfaces of the cover and the engine housing. For example, when a cover of glass-fibre reinforced plastic abuts an engine housing of a light metal, such as magnesium, such mutual movement will result in wear of the interengaging surfaces, primarily on the engine housing. Similar wear problems may occur even in the case of other combinations of material, such as when both the interengaging surfaces are made of reinforced plastic, or metal.